Automatic alarm for partially-deflated tires



Sept. 4, 1923.

A. J. MICHELIN.

AUTOMATIC ALARM FOR PARTIALLY DEFLATED TIRES Filed oct. 18, 1922zsneets-sneet 1 Spt. 4, 1923.

, A. J. MICHELIN AUTOMATIC ALARM FOR PARTIALLY DEFLATED TIRES 2Sheets-Sheet 2 Filed OCT... 18. 1922 u Aw m NE NAKHQ Patented Sept. 4,1923.

UNITED MES MMM orFIcag-" ANDR JULES MICHELIN, OF-RAEIS., FBNCEfAUTOMATIC ALTARM FDR'PARTIALLY-DEFLATED TIRES.

Application led October 1S, 19722; SerialfNo. 595,390.

T o @ZZ w hom/t may concern:

Be it known that I, ANDR Jennie MlcniaLrN, a citizen of the FrenchRepublic, residing at Paris, France, have invented certain newl andusetullmprovements in Automatic Alarms for Partially-Deflated Tires;Iand I do hereby declare the following to be;

a full, clear, and exact description of the in.- vention, such as willenableV others skilled in the art to Which it appertains tomake' and usethe same, l

My present. invention relates to improvements in apparatus for Warningthe chauffeur or driver of a vehicle provided with pneumatic tires whenthe pressure ot'- the air in the inner tube of said tire falls. belownormal, and prior to thelco-mplete deflation of the tire. In otherWordsit is intended to provide automatically operated apparatus whichwill advise the chauffeur,

not when the tire is down, but Whenthe pressure in the tire is so low asto threaten injurious effects at an ea-rly date but before suchinjurious effects take place.

ln such an apparatus it is desirable to provide compact, light andefficient apparatus which is not likely to be inthe way of theothervparts of the mechanism, and which will not be'conspicious orinterfere in any Wav `With the aesthetic appearance of the Wheel towhich it is attached. Bythe ar-l" paratus arranged to ire a cartridge,whichv is operatedY when the pressure 1n theinner.

tube falls below a predetermined limit,

My invention relates especially to improve-- ments on the device shownin my U. S.`

Patent No.` 1,367,490, granted February l, 1921, and entitled Automaticalarm vtor partially deflated tires.v

' The improvements referred te not ,01115T diminish the cest ofmanufacture, but inr erease'the Senstiveness of the-V device andeliminate the causent irregularity in operation, resulting from. theinequalities in the space between the edges ofthe 'beads 0f the tire,which space varies Jtor each size O gpneuniateftre@ In thepatent'referred tel the element actuated by the pressure ofthe air tube,which causes the release of thepercussion member, is placed bet-Ween theedges ofthe beads adjacent to the rim; While in. the present inventionthis element is mountf ed above the beads further inside the casing ofthe traeml-the dev-lee is. held in place by =means of'- a steel plateprovided Withv notches to engage on the 'innerv face of the tire casingand` hold the partssecurely in; place. K v y Furthermore, the presentiinvention simplifies the spring arrangement of the patentKA referred to,and employs a single springewhich serves simultaneously to balance thepneumatic pressure on the interior of the inner tube, and to force thepercussion member against the cartridge, thereby caulllgthe cartridgeito explode when the pneumatic pressure in the inner tube falls below asafety limit. r f

For practical purposes, the safety. limit may be deiined as2 kilograms,or aboutllt pounds of pneumatic pressure to the square inch.'

Thesev and the various other features of my present invention will behereinafterA more fully described and claimed. i'

My invention vvillbe more fully under-4 stood afterreterence toythevaccompanying drawingsyin which like parts are indicatedr by similarreference symbols throughout the several views, and invvvhich Figure lshowsl ya` cross section through the rimvand tire, and though theapparatus forgiving the alarm, and shows the appara-l tus inthey armedor cocked position.

Figure 2 is a detail View, on a larger scale, ot the alarm apparatusshown in Fig.y l` showing the same section as in said igure; the parts;being shown in the 'armed4 or cocked position as in Fig. 1.'v

Figure 3 is a similar View to Fig. "2, but shows the parts intheposition assumed whenthe arm is operated andthe cartridge hasbeen-tired; and l v Y.

Figure Showsl the method. of mounting: the-inflated tire having thealarm Connected? thereto on the rim of the wheel. the rimandi tire beingshown in dotted lines, and the alarm attachment. being shown in tulllines.

A representsthe Wheel bodywhich; is... shown as. of the .disk Wheeltype, tia-ligadas at a, and having said flange perforated as at a0.

B represents the rim which may be ot any suitable type, but is shown inFig. 1 as of the clincher-type.

C represents the tire casing, and D the inner or pneumatic tube which isinflated in the usual way.

E represents the body portion or housingof the alarm attachment which ishollowed as shown, and is provided with anlanged head c to engage theannular portion f ot the clamp piece F, which is preferably made in theform of a basket open top and bottom, and is provided with a series ofoutwardly" projecting bosses f adapted to engage the bead c of the tirecasing C, as will be hereinafter more fully described.

The head of the clamp piece Fis provided with an annular chamber f2inwhich the clamping ring H is mounted, which ring is screw-threaded, asat 7L, to engage the screw threads e on the clamp piece; and the saidring is provided with an overhanging rib t adapted to engage and firmlyhold in place the diaphragm G. This diaphragm may be made of thin metal,or other suitable material which will yieldv slightly under treatment,but will return to the normal position' when the pressure is released.

The body portion E is exteriorly screw threaded, as Aat e2, to engagethcclamp nut T which bears against the part f of the clamp piece F, andthis nut holds the body portion iirmly in the clamped piece. The bodyportion E is provided with a chamber F0, with a tapered base c3, abovewhich is mounted the wedge-shaped ring J, the bottom of which ring is soshaped that the top of the ring will lie in a plane at right angles tothe aXis of the housing.

K represents a series of balls, arranged as a crown, normally heldbetween the ring'J and the cup-shaped cap or bell M, whose head m isnormally pressed outwards under the action of the pneumatic pressure inthe inner tube D. This bell M is provided at its outer or open end withan annular tapered chamber m terminating in the plane tace fm2, parallelto the adjacent tace of the ring J.

This bell M may also be provided with an inwardly projecting lug mawhich projects into the coil spring N. This coil spring is held undercompression in the tubular plunger P, having the tiring pin goprojecting from its closed end p. Theopposite end of the plunger is opento permit the insertion and operation of the spring N. The exterior ofthis plunger is provided towards its open end with a tapered shouldervp2 adapted to engage the balls K and wedge the same outward whentheplunger is in the armed or cocked position shown in Fig. 2.

The housing E has its outer end e* perorated as at e5 to permit thepassage of the firing pin 07. T'he said housing is also screw threadednear its outer end as at c6.

Q represents the cartridge holder which is provided with a bore Q0 toreceive the cartridge, and with a recess g to receive the outer end otthe housing E to which the cartridge holder is attached. The cartridgeholder ris enlarged, as at g', for convenience in manipulation, and isscrewed on the housing, as shown in detail in Fig. 2.

S represents a gasket of rubber or other suitable material which tits ina notch t in the nut T. This nut is provided with an annular rib t whichbears against the metal washer S exterior to the gasket S. The nut T isprovided with internal screw threads t2 to engage the screw threads e6on the housing E.

When the parts are in the assembled position shown in Figs. 2 and 3 thehousing isl drawn outwards by turning on the nut T causing the bosses fof the clamp piece F to press outward on the tire casing and clamp thesame between said bosses and the adjacent edge of the rim, as shown mostclearly in Fig. l. Thus when the parts are assembled the alarmattachment will be securely held on the wheel, whether the tire beinflated o'r collapsed.

The alarm attachment may be located at any part of the rim of the wheel,but preferably located opposite the air valve WV, as shown in Fig. 4t,not only to balance the weight of the parts, but also to provide a moresymmetrical arrangement.

In assembling the device, the parts of the alarm apparatus shown in Fig.2 are inserted in the tire casing, except that the cartridge chamber Qand the nut T carrying the washer S and gasket S are removed from thehousing E; and the screw cap U is screwed on, to which cap .is attacheda cord or chain V. This cord or chain is rove through the opening in thewheel rim and the flange of the disk, thus serving to guide saidhousing` toward the hole in the rim, and the stem of the housing isdrawn up through said hole, as indicated in Fig. et. The tire and rimare shown in dotted lines in Fig. 4.

But, this device for guiding the housing may be omitted, it desired, andI do not claim it as a part of my invention.

After 'the stem of the housing has been properly located, the tire isinflated to a pressure above the minimum desired, the screwvcap U istaken ofi', and the nut T is screwed over the portion e of the housinguntil the alarm apparatus is rmly held in the position shown in Figs. 2and 3. Then the pressure on the inner tube exceeds the predeterminedminimum limit, the device may be armed b v Asimply pressing inwards onthe pin p until the tapered shoulder p2 WSSGS beyond the balls,` then itthe pressure these balls will be wedged outwards, under the action ofthetapered shoulder p2, into the annular channel betweenk the face m2 andthe ring J, permitting the free outward movement of the of the spring N.

It will be noted that the pneumatic pressure on the inner tube pressesthe bell outwards, and that the bell is pressed inwardsunder the actionof the spring N. By selecting a spring of the desired strength theapparatus may be adjusted, within limits, to Signal whenanyprcdetermined minimum pressure has been attained in the inner tube.Thus, I havek indicated two kilograms of pressure as the minimumpressure which should be permitted, but obviously a minimum pressurelarger than this may be provided for by increasing the power of thespring N.

It will be seen that a single spring serves to actuate the means forlocking the plunger in the armed position and for releasing said plungerwhen the pressure falls below a predetermined limit. Then the plunger isreleased it will fiy outwards, exploding the cartridge and signaling tothe chauffeur or driver that one of the tires is partially deflated.

It will be noted that with this arrangement the length et the spring,and the large surface ot the elements, subject to the pressure of theinner tube to hold the plunger cocked, or to release it` permit theattaining of great accuracy in the minimum pressure in the inner tube.Moreover, a very small movement of the diaphragm is required in eitherthe coclring or releasing operation.

It will be noted that the housing E is closed itself. and is completelyenclosed, thus protecting the parts from dust, rust, water, or otherdeteriorating causes which might impair or prevent the operation of thedevice.

lt will also be noted that in case of a blowout the alarm apparatuswillhold the tire casing on the rim and prevent same from being strippedfrom the rim. This is especially important when traveling at high speed,or traveling any length of time on a deflated tire.

lt will be obvious that various modiiications might be made in thehereinl described device, and in the construction, combination andarrangement of parts which could be plunger P under the action usedwithout departing from the spirit of my invention; and I do not mean tolimit the invention to such details except as particularly pointed outin the claims.

Having thus described my invention what I claim and desire to secure byLetters Patent ot the United States is v 1. An automatic alarm forindicating when the pressure in the inner tube of a pneumatic tirefalls` below a predetermined limit, comprising a housing having itsupper end projecting into the interior of the tire casing between thebeads, and its lower end projecting through the rim of the wheel, theupper end being open and provided with an enlarged chamber, and thelower end being axially perforated, a diaphragm closing said upper endand normally pressed upon by the inner tube of the tire, a bell slidablymounted in said chamber and'- normally engaging said diaphragm, aplunger slidably mounted in said housing and also slidablyk mounted insaid bell, a coil spring mounted in said plunger and normally pressingthe plunger in one direction and the bell in the other direction, thesaid bell being provided with a iaring mouth, and the said plunger beingprovided with an exterior tapered shoulder, and a crown of balls adaptedto be wedged between said flaring mouth and said tapered shoulder whenthe pneumatic pressure exceeds the spring pressure, but to be releasedwhen the pneumatic pressure falls` below the `spring pressure, and meansactuated by the release of said plunger for sounding an alarm. j

2. An automatic alarm for indicating when the pressure inthe inner tubeof a pneumatic tire falls below a predetermined limit, comprising ahousing having its upper end projecting in to the interior of the tirecasing between the beads, and its lower `end projecting through the rimot the wheel, the upper end being open and provided'with an enlargedchamber, and the lower end being axially perforated, a

diaphragm closing said upper end and normally pressed upon by the innertube of the tire, a bell slidably mounted in said charnber andnormallyengaging said diaphragm. a plungerr slidably mounted in said housing andalso slidablyr mounted in said bell, a coil spring mounted in saidplunger and normally pressing the plunger in one direction and the bellin the other direction, the said bell being provided with a flaringmouth, and the said plunger being provided with an exterior taperedshoulder, a ring wedge-shaped in cross section mounted in the base ofsaid chamber, and acrown oi balls supported on said ring and adapted tobe wedged between said Harinamouth and said tapered shoulder and saidringn when the pneumaticy pressure exceeds the spring pressure, but tobe released when the pneumatic pressure falls below the springlpressure, and means actuated by the release of said plunger for soundingan alarm.

3. An automatic alarm for indicating when the pressure in the inner tubeot a pneumatic tire falls below a predetermined limit, comprising ahousing having its upper end projecting into the interior ot the tirecasing between the beads, and its lower end projecting through the rimot the wheel, the upper end being open and provided with an enlargedchamber, and the lower end being axially perliorated, a diaphragmclosing` said upper end and normally pressed upon by the inner tube o1cthe tire, a bell slidably mounted in said chamber and normally engagingsaid diaphragm, a plunger provided with a tiring pin slidably mounted insaid housing` and also slidably mounted in said bell, a. coil springmounted in said plunger and normally pressing the plunger in onedirection and 'the bell in the other direction, the said bell beingprovided with a 'flaringr mouth, and the said plunger' being providedwith an exterior tapered shoulder, and a crown of balls adapted to bewedged between said Haring mouth and said tapered shoulder when thepneumatic pressure exceeds the spring pressure, but to be released whenthe pneumatic pressure tails below the spring pressure, with a capprovided with a cartridge chamber detachably connected to the lower endof said housing, and adapted to hold a. cartridge in the path oi theiiring pin, the said cartridge closing` the opening through the lowerend ot said housing.

Ll. An automatic alarm tor indicating when the pressure in the innertube ot a. pneumatic tire falls below a predetermined limit, comprisinga housing having its upper end projecting into the interior of the tirecasing between the beads, and its lower end projecting through the rimo'f the wheel, the upper end being open and provided with an enlargedchamber, and the lower end being axially perforated,y a diaphragmclosing said upper end and normally pressed upon by the inner tube ofthe tire, a bell slidably mounted in said chamber and normally engagingsaid diaphragm-n1 a plunger provided with a firing pin slidably mountedin said housing and also slidably mounted in said bell, a coil springmounted in said plunger and normally pressing the plunger in onedirection and the bell in the other direction. the said bell. beingprovided with a Haring mouth. and the said plunger being provided withan exterior tapered shoulder, a ring wedgeshaped in cross sectionmounted in the base of said chamber, and a crown of balls supported onsaid ring and adapted to be wedged between said flaring mouth and saidtapered Shoulder and said ring when the pneumatic pressure exceeds thespring pressure, but to be released when the pneumatic pressure 'fallsbelow the spring pressure, with a cap provided with a cartridge chamberdetachably connected to the lower end of said housing, and adapted tohold a cartridge in the path of the firing pin, the said cartridgeclosing the opening through the lower end of said housing.

5. An automatic alarm .tor indicatingI when the pressure in the innertube ot a pneumatic tire falls below a predetermined limit, comprising ahousing having its upper end projecting into the interior of the tirecasing between the beads, and its lower end projecting through the rimot the wheel, the upper end being open and provided with an enlargedchamber, and the lower end being axially perforated, a diaphragmclosingsaid upper end and normally pressed upon by the innerl tube ot'the tire. a bell slidably mounted in said chamber and normally engagingsaid diaphragm, means for securing said housing in place comprising aclamp piece held between said housing and the beads of the tire, and anut mounted on said housing on the inside ot the rim of the wheel, aplunger slidably mounted in said housing and also slidably mounted insaid bell, a coil spring mounted in sail plunger and normally pressingthe plunger in one direction and the bell in the other direction, thesaid bell being provided with a Haring mouth, and the said plunger beingprovided with an exterior tapered shoulder, and a crown of balls adaptedto be wedged between said Haring mouth and said tapered shoulder whenthe pneumatic pressure exceeds the spring pressure, but to be releasedwhen the pneumatic pressure falls below the spring pressure, and meansactuated Aby the release of. said plunger for sounding` an alarm.

6. An automatic alarm for indicating when the pressure in the inner tubeot" a pneumatic tire falls below a predetermined limit, comprising ahousing having its upper end projecting into the interior ot the tirecasing between the beads, and its lower end projecting through the rimof the wheel, the upper end being open and provided with an enlargedchamber` and the lower end being axially pretorated. a bell slidablymounted in said Chamber, a plunger slidably mounted in said housingandalso slidably mounted in said bell, coil spring mounted in said plungerand normally pressing the plunger in one direction and the bell in theother direction, the said bell being provided with a flaring mouth, andthe said plunger being provided wth an exteror tapered shoulder, and acrown of balls adapted to be wedged between said flaring mouth and saidtapered shoulder when the pneumatic pressure exceeds the pressure, butto be released when the pneumatic pressure falls below the springpressure, and means actuated by the release of said plunger for soundingan alarm.

7. An automatic alarm for indicating when the pressure in the inner tubeof a pneumatic tire falls below a predetermined limit, comprising ahousing having its upper end projecting into the interior of the tirecasing between the beads, and its lower end projecting through the rimof the wheel, the upper end being open and provided with an enlargedchamber, and the lower end being axially perforated, a bell slidablymounted in said chamber, a plunger slidablyv mounted in said housing andalso slidably mounted in said bell, a coil spring mounted in saidplunger and normally pressing the plunger in one direction and the bellin the other direction, the said bell being provided with a flaringmouth, and the said plunger being provided withan exterior taperedshoulder, a ring wedgeshaped in cross section mounted in the base ofsaid chamber, and a crown of balls supported on said ring and adapted tobe wedged between said flaring mouth and said tapered shoulder and saidring when the pneumatic pressure exceeds the spring presf sure, but tobe released when the penuniatic pressure falls below the springpressure, and means actuated by the release of said plunger for soundingan alarm.

8. An automatic alarm for indicating i when the pressure in the innertube of a pneumatic tire falls below a predetermined limit, comprising ahousing having its upper end projecting into the interior of the tirecasing between the beads, and its lower end projecting through the rimof the wheel, the upper end being open and provided with an enlargedchamber, and the lower end being axially perforated, a bell slidablymounted in said chamber, a plunger provided with a firing pin slidablymounted in said housing and also slidably mounted in said bell, a coilspring mounted in said plunger and normally pressing the plunger in onedirection and the bell in the other direction, the said bell beingprovided with a flaring mouth, and the said plunger being provided withan exterior tapered shoulder, and a crown of balls adapted to be wedgedbetween said flaring mouth and said tapered shoulder when the pneumaticpressure exceeds the spring pressure, but to be released when the`pneumatic pressure falls below the spring pressure, with the cartridgechamber connected to said housing adapted to contain a cartridge. y

9. An automatic alarm for indicating when ,the pressure in the innertube of a pneumatic a jecting into the interior ot the tire casingbetween the beads, and its lower end pro-l jecting through the rim ofthe wheel, the upper end being open andprovided with an enlargedchamber, and the lower end being axially perforated, a bell slidablymounted in said chamber, a plunger provided with a firing pin slidablymounted in said housing and also slidably mounted in said bell, a coilspring mounted in said plunger and normally pressing the plunger in onedirection and the bell inthe other direction, the said bell beingprovided with a flaring mouth, and the said plunger being provided withan exterior tapered shoulder, and a crown of balls adapted to be wedgedbetween -said llaring mouth and said tapered shoulder when the pneumaticpressure exceeds the spring pressure, butto lbe released when thepneumatic pressureA falls below the spring pressure, with a cap providedwith a cartridge chamber detachably connected to the lower end of saidhousing, and adapted to hold a cartridge, in the path of the firing pin,the said cartridge closing the opening through the lower end `of saidhousing.

10. An automatic alarm for indicating when the`pressure in the innertubeota pneumatic tire falls below a predetermined limit, comprising ahousing having its upper end projecting into the interior of the tirecasing between the beads, and its lower end projecting through the rimof the wheel, the upper end being open and provided with an enlargedchamber, and the lower endvbeino axially perforated, a bell slidablymounted in said chamber, means forsecuring said housing in'placecomprising a clamp piece held between said housing and thebeads of thetire, and a nut mounted on -said housing on the inside of the rim of thewheel, a plunger slidably mounted in said housing and also slidablymounted in said bell, a 4coil p i spring mounted in said plunger andnormally pressing the plunger in one direction and the bell in the otherdirection,A the said bell being provided with a flaring mouth, and thesaid plunger being provided with an exterior tapered shoulder, and acrown-of balls adapted to be wedged between said flaring mouth' and saidtapered kshoulder when the pneumatic pressure exceeds the springpressure, but to be released when the pneumatic pressure falls below thespring pressure, with means actuated by said plunger from making anaudible signal.

-4 ANDR JULEs MICHELIN.

